Today we will discuss about single point cutting tool geometry and how to designate it.
A single point cutting tool is widely used in metal cutting industries for
forming required shape. It is used on lathe and shaper machining for performing operation like turning, facing, chamfering, boring shaping etc. This cutting
tool has a single cutting point which cut the work piece by rubbing over it. Today
we will learn about geometry of this tool and further we will discuss about how
to designate it.
Single Point Cutting Tool:
A single
point cutting tool consist Flank, face, cutting edge, nose, rack angle, clearance
angle, cutting edge angle etc. All of these parts control the cutting condition,
tool life and cutting speed of tool. These parts describe as follow.
Geometry and Tool angles of Single Point Cutting Tool:
1. Shank:
The main
body of the tool is known as shank. It is the backward part of tool which is
hold by tool post.
2. Face:
The top surface
tool on which chips passes after cutting is known as face. It is the horizontal
surface adjacent of cutting edges.
Flank:
Sometime
flank is also known as cutting face. It is the vertical surface adjacent to
cutting edge. According to cutting edge, there are two flank side flank and end
flank.
3. Nose or Cutting point:
The point
where both cutting edge meets known as cutting point or nose. It is front of
the tool.
4. Base:
The bottom
surface of tool is known as base. It is just opposite surface of face.
5. Heel:
It is a intersecting
line of face and base.
6. End cutting edge angle:
The angle
between end cutting edge or flank to the plane perpendicular to the side of
shank is known as end cutting angle.
7. Side cutting edge angle:
The angle between
the side cutting edge or flank to the plane parallel to the side of the shank known
as side cutting edge angle.
8. Back rake angle:
The angle
form to smooth flowing of chips from face, known as rack angle. It allows to
smooth flow of chips. Back rack angle is the angle between face and the plane
perpendicular to the end cutting edge.
9. Side rack angle:
The angle
between the face and plane perpendicular to the side cutting edge is known as
side rack angle. It allows chips to flow smoothly when material cut by side
cutting edge.
10. End relief angle:
It is also
known as clearance angle. It is the angle which avoids tool wear. It avoid the rubbing
of flank with work piece. End cutting angle made by end flank to the plane
perpendicular to base.
11. Side relief angle:
It is the
angle made by the side flank to the plane perpendicular to the base. It avoid
rubbing of side flank with work piece.
12. Nose radius:
The
intersecting area of both cutting edges is known as nose of the tool. It does
not have a sharp profile. Sharp profile may cause scratches on work piece which
gives poor surface finish. To avoid this and obtain good surface finish this
area is at some radius known as nose radius. If the radius is too small is
gives poor surface finish and if it is too large gives poor
For better understanding watch the video given below.
For better understanding watch the video given below.
Signature of single point cutting tool:
According to the american standard a tool can
be designate by seven parameters arranged in a specific manner. It is also
known as tool signature. These parameters are all angles and nose radius.
If a tool has shown by 2, 9, 5, 5, 9, 11, 3 it means
If a tool has shown by 2, 9, 5, 5, 9, 11, 3 it means
Back rack
angle:
Side rack angle:
End relief
angle:
Side relief
angle:
End cutting edge
angle: 9°
Side cutting
edge angle:
Nose radius:
These parameters
are internationally used to signature of a tool.
Today we
have learned about single point cutting tool nomenclature, angle, geometry and signature. If you have any query regarding
this article, ask by commenting.